The present invention pertains generally to concealed fastening means for removably securing a picture frame or its like to a wall surface in a theftproof manner.
Important features of a frame mounting system is that it be concealed from view and that, in commercial uses, discourages theft. Toward these ends U.S. Pat. No. 4,385,744 discloses a frame hanging system utilizing both Z-shaped clips and a companion latching device including an arm which swings into position behind a picture frame flange to prevent frame movement away from an adjacent wall. A cam surface on the arm permits the arm to move in response to the frame during frame movement toward a wall. A tool for frame release from a wall is necessary and with the tool having a right angular end member which requires that the wall attached frame must always be outwardly positionable from the wall surface a distance to permit tool end member insertion. A gap between frame and wall is undesirable from an aesthetic and from a vibration standpoint. Additionally the foregoing system provides no means for marking a wall for precisely locating fasteners during installation.
Other frame installing devices include fasteners with T-shaped heads which are rotated 90 degrees after insertion into a tubular frame channel to prevent frame movement away from a wall.